Electrical switch.



O. S. WALKER IIL I. F. WILLIAMS.

ELECTRICAL SWITCH.

APPLICATION FILED MAR. I4, I9I4.

1,162,831. Patented Dec. T, 1915.

- coils, in order to ASSIGNORS T0 O. S. WALKER C0., TION OF MYASSACHUSETTS..

ELECTRICAL SWITCH.

Specification of Letters Patent.

Patented Dec. '7, 1915.

Application led March 14, 1914. Serial N o. 824,794.

To all -uLom t may Concern:

Be it known that we, OAKLEY S. WALKER and ISAAC F. lVlLLIAiIs, both of Worcester, in the county of Yorcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in Electrical Switches, of whichv the following, taken in connection with the accompanying drawings, is a specification.

The present invention relates to an electrical switch adapted to control the flow of electric current through a plurality of coils or a plurality of sets of coils, and in the present instance is shown in connection with the magnetizing coils of a magnetic chuck.

The invention consists in the construction and arrangement of parts as hereinafter set forth, by means of which the said coils or sets of coils may be connected either in series or in multiple, as desired.

Furthermore, the invention contemplates the provision of a switch of the above character, adapted to effect, upon being operated to release the work from the chuck, a reversal of the current through the said accomplish the complete demagnetization of the chuck.

eferring to the drawings, Figure 1 is a plan view of a switch embodying our invention, the same being shown in connection with a diagrammatic representation of a double coil magnetic chucka F ig. 2 is a side view of the switch in one4 of its operating positions. Fig. 3 is a view similar to Fig. 2 of the switch in its other operating position.

Like reference characters refer to like parts in the several figures.

The numeral 1 designates a magnetic chuck, the faceplate of which, adapted for the support of the work, is removed in Fig. l to disclose a pair of magnetizing coils 2, 3, contained within the interior chamber of the chuck, in the usual manner. Obviously, the coils 2 and 3 are capable of any desired arrangement within the chuck, the details of construction of the latter forming no part of the present invention. Furthermore, it will be apparent that each coil of the pair .to which the switch is connected may bev made up of any number of smaller coils, connected In any desired manner. For the purpose of illustration, however, we have shown two independent similarly wound coils 2 and 3; the inner and outer terminals of coil 2 are denoted by reference characters 4 and 5 respectively, while the corresponding terminals of coil 3 are denoted by the reference characters 6 and 7 respectively.

The switch for controlling the flow of current through the coils 2 and 3 is embodied in the present instance in a two pole knife. double throw switch, the operative parts of which are mounted on a base 8 of suitable nonconducting material. Oppositely disposed metallic standards 9 and 10, secured to said base and having suitable terminal posts for the connection of wires thereto, serve as pivotal supports for the two parallel blades 11 and 12, respectively, of the switch, which are connected to rock in unison vby spacing blocks 13 and 11 of suitable nonconducting material. The la'ter are provided with alined transverse apertures to receive a metallic bar or rod 15, disposed parallel to and between the blades 11 and 12, and having on its outer end an insulatinghandle 16, by means of which the connected blades 11 and 12 are rocked in unison about their pivots.

At one side of the standards 9 and 10, the base 8 supports two pairs of oppositely disposed bifurcated contacts 17, 18, and 19, 20, respectively, adapted to receive between their jaws the edges of the correspondingly alined blades 11 and 12 when the latter are rocked into the position shown in Fig. 2, the blade 11 connecting the contacts 1T and 19, and the blade 12 connecting the contacts 18 and 20. In this position of the switch the course of the current carried by the leads Y 21 and 22, which are connected to suitable terminal posts on the contacts 1T and 18, is indicated by the full line arrows. as follows:-from Contact 17, along blade 11 to contact 19, where it divides, a portion passing through wire 23, coil 2,r and returning through wire 26 to standard 10 and blade 12. The other portion flows from Contact 19, along blade 11 to standard 9, and thence through wire 25, coil 3 and back through wire 2l to contact 20 and blade 12, joining the rst portion and passing with it through contact 18 and lead The coils 2 and y3 are thereby connected in multiple, a separate portion of the current passing through each,l

and it will be noted that th'e direction of flow of the current is the" same 'in each, namely, from theouter terminals 5 and 7,

`nection 27 to contact 29, thence .to the inner terminals 4 and 6, respectively,

whereby the magnets energized by said coils are of like polarity.

The contacts 17 and 18 are respectively connected by diagonally disposed connections 27 and 28 passing through the base 8, with a similar pair of contacts 29 and 3() mounted on the other side of the standards 9 and 10 and adapted to' receive the other ends of blades 12 and 11, when the same are rocked into the position shown in Fig. 3.

A pair of separated conductors 31 and 32, carried by the base 8 and out of the path of blades 11 and 12, are connected with the contacts 19 and 20, respectively, by connections 33 and 34 passing through the base. In the position of the switch shown in Fig. 3, the space between said conductors is bridged by the bar 15, which contacts with each of them, when interposed betweenY them. The course of the current, indicated by the dotted line arrows in'-Fig. 1, is then as' follows from contact 17 through conalong blade 12 and through standard 10, wire 26 to coil 2, returning through wire 23 to contact 19 and passing through connection 33 to conductor 31. From this point it passes across bar 15 to conductor 32 and thence through connection 34 to contact 20, passing through wire 24 and coil 3 and returning through Wire 25 to standard 9; thence along blade 11 to contact 30, from which it is led by con` nection 2S tocontact 18 and lead 22. The coils 2 and 3 are thereby connected in series, the same current passing through each, and it will be particularly noted, in the same direction namely, from the inner terminals 4 and 6 to the outer terminals 5 and 7, respectively.

It will be noted that the direction of the current through the coils when connected, as above described, in series, is opposite to the direction of the current through them when they are connected in multiple, in the other, and first described position of the switch. From this condition it follows that in either case, when it is desired to release the work held'by the chuck, the switch is thrown from whichever operative position it may be in, to its other operative position, and immediately thereafter to its neutral horizontal` position, shown in-dotted lines in Fig. 3. This action of the switch effects a momentary reversal lof the current through the coils immediately after their disconnection from the source of electrical supply,

with a consequent complete demagnetization of the magnets energized by said coils.

It will be apparent that the present invention is applicable to any type of magnetic chucks, in which there is provided a plurality of coils or a plurality of sets of coils. l/Ve'have shown, for the purposes of illustration, a stationary chuck; obviously a revolving or reciprocating chuck could as well be employed, by connecting the terminals 4, 5, 6 and 7 of the coils to conducting rings or bars attached to the chuck, and making contact with stationary brushes connected with wires 26, 23, 24 and 25 respectively, in the manner well known in electric transmission.

We claim,

1. The combination with a pair of coils, of a switch comprising a pair of movable blades, each connected with one terminal of a coil, a pair of contacts for said blades, in connection with an electrical supply, a second pair of contacts for said blades, in connection with the remaining terminals of said coils, a third pair of contacts for said blades oppositely connected to said first pair of contacts, and a pair of conductors in connection with the second pair of contacts, adapted to be connectedl together when said blades engage the third pair oficontacts.

2. An electrical switch, comprising pivoted switch blades, contacts for the ends of said blades at one side of the pivotal aXis thereof, contacts for said blades between said axis and said first set of contacts, contacts for the other ends of said blades, connections between the opposite contacts of said first and third sets of contacts, a pair of separated conductors each in electrical connection with the corresponding contact of said second set .of contacts, and means carried by said blades for electrically connecting said conductors.

3. An electrical switch, comprising a pair of pivoted switch blades, movable into two operative positions, two pairs of contacts for said blades in one of said positions, a pair of contacts for said blades in the other position, a pair of separated conductors, and means carried by said blades for electrically connecting said conductors in said last mentioned position of said blades.

OAKLEY S WALKER. ISAAC FOVVLER WILLIAMS. Witnesses:

PENELOPE COMBERBACH, NELLIE WHALEN. 

